1. Field of the Invention
The present invention relates to an apparatus and a method for testing an information processing device such as a work station or a personal computer (abbreviated to PC hereafter), used in combination with a memory unit using a disk-type medium (described as a disk unit hereafter).
2. Description of the Related Art
As the typical disk unit used in the information processing device (computer), a hard disk drive (abbreviated to HDD hereafter) is well known. FIG. 1A shows an arrangement of a magnetic disk and a read/write head which is a storage medium of the HDD internally installed in the PC.
In FIG. 1A, data are stored on an upper magnetic disk 1, and positioning information is stored on a lower magnetic disk 1. Based on the positioning information on the lower magnetic disk, the HDD accesses data on the upper magnetic disk 1.
Recently, the HDD has become smaller in size and denser in assembly, and the head 2 comes very close to the surface of the magnetic disk 1, with a distance equal to or less than 0.1 .mu.m. Owing to vibration or impact, the head 2 may come into contact with the S magnetic disk 1, thereby causing damage to the magnetic disk 1 and the data on the magnetic disk 1.
FIG. 1B shows a plan view of the magnetic disk 1. Normally, when a drive motor of the HDD stops, the head 2 stays at a position in a texture area 4. The texture area 4 is located on the outer side of a data storage area 3 on the magnetic disk 1. So long as the head 2 stays in the texture area 4, the data will not be damaged by vibration and the like. The texture area 4 may also be formed in an inner area 5 of the data recording area 3.
Many of the operation testing processes in the PC during manufacturing are performed in a completed assembly in which the HDD is installed. The testing of the PC is generally executed by a plurality of function testing processes. During these testing processes, since the PCs are tested while they are being put on a pallet and transported on a conveyor or by rollers, vibrations and collisions between pallets frequently occur.
During transportation of the PCs, the data storage area 3 in the magnetic disk 1 can be damaged by contact from the head 2, resulting in damage to data stored in the data storage area 3. In order to prevent the data on the HDD from being damaged, the following countermeasures are conventionally taken:
(1) To avoid vibrations from the rollers during transportation, the rollers should be exactly set horizontally.
(2) To avoid vibrations and collisions between pallets during transportation, the pallets are moved slowly.
(3) Operators are instructed to disconnect the power supply and only to move a pallet after fifteen seconds, when the HDD motor has definitely stopped in the PC.
In the conventional testing processes, however, there are such problems as described below:
(1) In order to set the rollers more precisely in the horizontal direction, expensive equipment is required.
(2) When the pallets are set to move slowly, the total output of products decreases.
(3) When the necessary time for the HDD motor to be stopped is secured, the total number of products decreases because it takes time to transport the products to the subsequent process. Further, the operators do not always wait to ensure the HDD motor has stopped before moving the pallets. They might start moving the pallets before the HDD motor stops, thereby causing damage to the stored data.